26 research outputs found
Total and tropospheric ozone changes: observations and numerical modelling
A survey has been made of total and tropospheric ozone dynamics in the context of its impacts on climate, human health and ecosystems. Observation data on total ozone content (TOZ) in the atmosphere and relevant numerical modelling results have been discussed as well as similar information for tropospheric ozone, whose formation and changes are being determined by quite different causes. A
necessity has been emphasized to get more adequate global observational data on TOZ and tropospheric ozone (this is especially important in the latter case, because information on tropospheric ozone is far from being complete). Unsolved problems relevant to both total and tropospheric ozone have been briefly considered
Crop Updates 2000 - Cereals part 1
This session covers eleven papers from different authors:
PLENARY PAPERS
1. New Wheat for a Secure, Sustainable Future, Timothy G. Reeves, Sanjaya Rajaram, Maarten van Ginkel, Richard Trethowan, Hans-Joachim Braun, and Kelly Cassaday, International Maize and Wheat Improvement Centre (CIMMYT)
2. Managing Cereal Rusts - a National Perspective, R.A. McIntosh, University of Sydney Plant Breeding Institute, New South Wales
3. Managing Cereal Rusts in 2000 - a regional imperative, R. Loughman, Agriculture Western Australia
4. Is nutrition the answer to wheat after canola problems?Ross Brennan1, Bill Bowden1, Mike Bolland1, Zed Rengel2 and David Isbister2 1 Agriculture Western Australia 2University of Western Australia
5. Improved Sandplain Cropping Systems by Controlled Traffic, Dr Paul Blackwell, Agriculture Western Australia
6. Raised bed farming for improved cropping of waterlogged soils, Derk Bakker, Greg Hamilton, David Houlbrooke, Cliff Spann and Doug Rowe, Agriculture Western Australia
7. Banded Urea increased wheat yields, Patrick Gethin, Stephen Loss, Frank Boetel, and Tim OâDea, CSBP futurefarm
8. Flexi N is as effective as Urea on wheat and canola, Frank Boetel, Stephen Loss, Patrick Gethin, and Tim OâDea CSBP futurefarm
9. Why potassium may reduce cereal leaf disease, Noeleen Edwards, Agriculture Western Australia
10, Trace elements, Wayne Pluske CSBP futurefarm, and Ross BrennanAgriculture Western Australia
11. Historical Nutrient Balance at Paddock and Whole Farm scales for typical wheatbelt farms in the Dowerin - Wongan Hills area, M.T.F. Wong, K. Wittwer and H. Zhang Precision Agriculture Research Group, CSIRO Land and Wate
Genomic insights into rapid speciation within the worldâs largest tree genus Syzygium
Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification
Biosecurity and Yield Improvement Technologies Are Strategic Complements in the Fight against Food Insecurity
The delivery of food security via continued crop yield improvement alone is not an effective food security strategy, and must be supported by pre- and post-border biosecurity policies to guard against perverse outcomes. In the wake of the green revolution, yield gains have been in steady decline, while post-harvest crop losses have increased as a result of insufficiently resourced and uncoordinated efforts to control spoilage throughout global transport and storage networks. This paper focuses on the role that biosecurity is set to play in future food security by preventing both pre- and post-harvest losses, thereby protecting crop yield. We model biosecurity as a food security technology that may complement conventional yield improvement policies if the gains in global farm profits are sufficient to offset the costs of implementation and maintenance. Using phytosanitary measures that slow global spread of the Ug99 strain of wheat stem rust as an example of pre-border biosecurity risk mitigation and combining it with post-border surveillance and invasive alien species control efforts, we estimate global farm profitability may be improved by over US$4.5 billion per annum
Genomic insights into rapid speciation within the world's largest tree genus Syzygium
Acknowledgements Y.W.L. was supported by a postgraduate scholarship research grant from the Ministry of National Development, Singapore awarded through the National Parks Board, Singapore (NParks; NParksâ Garden City Fund). Principal research funding from NParks and the School of Biological Sciences (SBS), Nanyang Technological University (NTU), Singapore, is acknowledged. We thank Peter Preiser, Associate Vice President for Biomedical and Life Sciences, for facilitating NTU support, and Kenneth Er, CEO of NParks, for facilitating research funding through that organisation. V.A.A. and C.L. were funded by SBS, NTU for a one-year research leave. V.A.A. and C.L. also acknowledge support from the United States National Science Foundation (grants 2030871 and 1854550, respectively). S.R. was supported by a postdoctoral research fellowship under the NTU Strategic Plant Programme. S.R. and N.R.W.C. acknowledge funding from NTU start-up and the Academy of Finland (decisions 318288, 319947) grants to J.S. Fieldwork conducted by Y.W.L. was supported by an Indonesian Government RISTEK research permit (Application ID: 1517217008) and an Access License from the Sabah State government [JKM/MBS.1000-2/2JLD.7(84)]. T.N.C.V. is grateful to the AssemblĂ©e de la Province Nord and AssemblĂ©e de la Province Sud (New Caledonia) for facilitating relevant collection permits. A.N. was partly supported by the Research Project Promotion Grant (Strategic Research Grant No. 17SP01302) from the University of the Ryukyus, and partly by the Environment Research and Technology Development Fund (JPMEERF20204003) from the Environmental Restoration and Conservation Agency of Japan. Fieldwork in Fiji conducted by R.B. was hosted and facilitated by Elina Nabubuniyaka-Young (The Pacific Communityâs Centre for Pacific Crops and Trees, Fiji). We thank the NTU-Smithsonian Partnership for tree data obtained for the Bukit Timah Nature Reserve (BTNR) long-term forest dynamics plots. Administrative support provided by Mui Hwang Khoo-Woon and Peter Ang at the molecular laboratory of the Singapore Botanic Gardens (SBG) is acknowledged. Rosie Woods and Imalka Kahandawala (DNA and Tissue Bank, Royal Botanic Gardens, Kew) facilitated additional DNA samples. Daniel Thomas (SBG) and Yan Yu (Sichuan University) commented on biogeographical analyses. NovogeneAIT in Singapore is acknowledged for personalised sequencing service.Peer reviewedPublisher PD
Genomic insights into rapid speciation within the world's largest tree genus Syzygium
The relative importance of the mechanisms underlying species radiation remains unclear. Here, the authors combine reference genome assembly and population genetics analyses to show that neutral forces have contributed to the radiation of the most species-rich tree genus Syzygium. Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification.Peer reviewe
Listening to lions : animal-borne acoustic sensors improve bio-logger calibration and behaviour classification performance
Efforts to better understand patterns of animal behaviour have often been restricted by
several environmental, human and experimental limitations associated with the collection
of animal behavioural data. The introduction of new bio-logging technology has offered
an alternative means of recording animal behaviour continuously and is being used
in an increasing number of studies. Accurately calibrating these bio-loggers, however,
still remains a challenge in many cases. Using lions as an example species, we test
how audio recordings from animal-borne acoustic sensors can improve calibration and
behaviour classification. Through a collaborative effort between computer scientists,
engineers, and zoologists, custom designed acoustic bio-loggers were fitted to eight
lions and recorded audio simultaneously with accelerometer and magnetometer data.
Audio recordings were then used as the source of ground truth to train random forest
classification models as well as to provide additional predictor variables for behaviour
classification. We demonstrated near-perfect classification performance for five lion
behaviour classes when all component variables were combined, with an average per-
class precision of 98.5%. Using accelerometer features only, the audio-trained classifier
predicted behaviours with an average per-class precision of 94.3%. On-animal audio
recordings are therefore able to provide a valuable source of ground-truth for calibrating
bio-loggers while also offering additional predictive features for increasing the accuracy of
behaviour classification. This technological innovation has wide ranging application and
provides a useful tool for behavioural ecologists wishing to collect fine scale behavioural
data for animal research and conservation.Audio 1 | Eating.Audio 2 | Drinking.Audio 3 | Fast.Audio 4 | Slow.Audio 5 | Stationary.The John Fell Fund and the Beit Trust.http://www.frontiersin.org/Ecology_and_Evolutionam2019Mammal Research InstituteZoology and Entomolog
Vocal discrimination of African lions and its potential for collar-free tracking
International audiencePrevious research has shown that African lions (Panthera leo) have the ability to discriminate between conspecific vocalisations, but little is known about how individual identity is conveyed in the spectral structure of roars. Using acoustic â accelerometer biologgers that allow vocalisations to be reliably associated with individual identity, we test for vocal individuality in the fundamental frequency (f0) of roars from 5 male lions, firstly by comparing simple f0 summary features and secondly by modelling the temporal pattern of the f0 contour. We then assess the application of this method for discriminating between individuals using passive acoustic monitoring. Results indicate that f0 summary features only allow for vocal discrimination with 70.7% accuracy. By comparison, vocal discrimination can be achieved with an accuracy of 91.5% based on individual differences in the temporal pattern of the f0 sequence. We further demonstrate that passively recorded lion roars can be localised and differentiated with similar accuracy. The existence of individually unique f0 contours in lion roars and their relatively lower attenuation indicates a likely mechanism enabling individual lions to identify conspecifics over long distances. These differences can be exploited by researchers to track individuals across the landscape and thereby supplement conventional lion monitoring approaches
Vocal discrimination of African lions and its potential for collar-free tracking
Previous research has shown that African lions (Panthera leo) have the ability to discriminate between conspecific vocalisations, but little is known about how individual identity is conveyed in the spectral structure of roars. Using acoustic â accelerometer biologgers that allow vocalisations to be reliably associated with individual identity, we test for vocal individuality in the fundamental frequency (f0) of roars from 5 male lions, firstly by comparing simple f0 summary features and secondly by modelling the temporal pattern of the f0 contour. We then assess the application of this method for discriminating between individuals using passive acoustic monitoring. Results indicate that f0 summary features only allow for vocal discrimination with 70.7% accuracy. By comparison, vocal discrimination can be achieved with an accuracy of 91.5% based on individual differences in the temporal pattern of the f0 sequence. We further demonstrate that passively recorded lion roars can be localised and differentiated with similar accuracy. The existence of individually unique f0 contours in lion roars and their relatively lower attenuation indicates a likely mechanism enabling individual lions to identify conspecifics over long distances. These differences can be exploited by researchers to track individuals across the landscape and thereby supplement conventional lion monitoring approaches.The John Fell Fund, University of Oxford and the Beit Trust.http://www.tandfonline.comtoc/tbio202021-10-02hj2021Mammal Research InstituteZoology and Entomolog